When occured: 

Tue, 1947-01-21

A rule change that allows voting only for players who were active after 1921 produces four new Hall of Fame members: catcher Mickey Cochrane, second baseman Frankie Frisch, and pitchers Lefty Grove and Carl Hubbell, all former Most Valuable Players and World Series winners. Pie Traynor misses selection by two votes. Hubbell was forbidden by Ty Cobb to throw his screwball in Detroit's farm system, but used it to win 253 games for the New York Giants; Frisch went to the World Series eight times and batted .316 over 19 seasons; Grove won 300 games, and his battery-mate Cochrane retired with .320, the highest lifetimebatting average of any catcher.